Zhang Jing, Tan Ying, Feng Liang, Ni Zhunan, Wang Junlin, Cai Zengxuan
Zhejiang Center for Disease Control and Prevention, Hangzhou 310051, China.
Wei Sheng Yan Jiu. 2020 Mar;49(2):267-271. doi: 10.19813/j.cnki.weishengyanjiu.2020.02.017.
To establish a method for determination of thiram, propineb and metiram in mushroom samples by gas chromatography-mass spectrometry(GC-MS).
Insoluble heavy metal salts were converted into water-soluble sodium salts by alkaline buffer with strong chelating agents. Dithiocarbamates can be converted into different methyl ester compounds with ion pair methylation. The GC separation was performed on a DB-5 MS capillary column(30 m×0. 25 mm, 0. 25 μm). The pesticides were detected by GC-MS with selective ion monitoring(SIM) and quantified by external standard of working curve method. Methodsological verification was carried out based on optimized sample pretreatment and GC-MS condition.
The concentrations of dithiocarbamates exhibited a good linear relationship with GC-MS within a certain range. The limits of detection of thiram, propineb and metiram were 0. 01, 0. 05 and 0. 05 mg/kg, respectively. Furthermore, the average recoveries were from 76. 98% to 93. 52%, and the maximum relative standard deviation was 11. 54%(n=6).
This method is simple, sensitive, accurate and reliable. All the indices meet the requirements of pesticide residue detection.
建立气相色谱 - 质谱联用（GC-MS）法测定蘑菇样品中福美双、丙森锌和代森联的方法。
用含强螯合剂的碱性缓冲液将不溶性重金属盐转化为水溶性钠盐。二硫代氨基甲酸盐可通过离子对甲基化转化为不同的甲酯化合物。采用DB-5 MS毛细管柱（30 m×0.25 mm，0.25 μm）进行GC分离。通过GC-MS采用选择离子监测（SIM）模式检测农药，并采用工作曲线外标法进行定量。基于优化后的样品前处理和GC-MS条件进行方法学验证。
二硫代氨基甲酸盐浓度在一定范围内与GC-MS呈现良好的线性关系。福美双、丙森锌和代森联的检出限分别为0.01、0.05和0.05 mg/kg。此外，平均回收率为76.98%至93.52%，最大相对标准偏差为11.54%（n = 6）。
该方法简便、灵敏、准确、可靠。各项指标均符合农药残留检测要求。
